1. Field of the Invention
The present invention relates to a door lock apparatus, and more particularly, to an unlock transmission mechanism applicable to escape doors or the like which facilitates easy and direct exit therefrom.
2. General Background
For maximum safety an escape door requires a latch that is simply and quickly operated yet is effective to resist opening by any person on the outside in case of a fire or forced entry. In short, safety with respect to these kinds of escape doors, and latches therefor, involves the dual consideration of easy exit for the occupant but difficult entry in undesired situations.
FIG. 1 depicts a basic construction of a known escape door 1 including a door handle mechanism 6, a push handle mechanism 5, an unlock transmission mechanism 2, an upper bolt link mechanism 4 and a lower bolt link mechanism 3. The door handle mechanism 6, the push handle mechanism 5, the upper bolt link mechanism 4 and the lower bolt link mechanism 3 are all connected to the unlock transmission mechanism 2, enabling the door handle mechanism 6 to move relative to the upper bolt link mechanism 4 and the lower bolt link mechanism 3 through the unlock transmission mechanism 2, and also the push handle mechanism 5 to move relative to the upper bolt link mechanism 4 and the lower bolt link mechanism 3 through the unlock transmission mechanism 2. Moreover, the push handle mechanism 5, the unlock transmission mechanism 2, the upper bolt link mechanism 4 and the lower bolt link mechanism 3 are disposed on the same side of the escape exit door, while the door handle mechanism 6 is installed on an opposite side thereof.
FIG. 2 is an exploded diagram illustrating an unlock transmission mechanism for escape doors as depicted in FIG. 1. The unlock transmission mechanism 2 for escape doors consists of a base 20; a second drive unit 22 having a base body 220 and two turning portions 221, wherein the base body 220 is fixedly disposed on the base 20, each of the two turning portions 221 being pivotally connected to the base body 220 respectively at corresponding positions and one end of each of the two turning portions 221 being coupled to one another by a spring; a transmission member 21 having a sliding board 210 and two detent protruding cylinders 211, wherein the sliding board 210 is slidably disposed within the second drive unit 22 of the base body 220, and the two detent protruding cylinders 211 are each disposed at two ends of the sliding board 211 with an interval therebetween larger than a largest distance between the tips of the two turning portions 221; a first drive unit 23 having a driving portion 230 and a pivot portion 231, the driving portion 230 being pivoted on the base 20 via the pivot portion 231 and one end thereof moving relative to the sliding board 210 of the transmission member 21, wherein two symmetrical limiting protrusions 200 are each disposed on the base 20 at positions close to the two sides of the pivot portion 231 respectively, for limiting rotation of the driving portion 230 within the range of relative movement to the sliding block, wherein the pivot portion 231 moves relative to the door handle mechanism 6 of the escape door.
When the door handle is rotated by a user, the door handle mechanism 6 moves relative to the transmission member 21 via the first drive unit 23. Conversely, when the door handle is pressed by the user, the push handle mechanism 5 moves relative to the transmission member 21 via the second drive unit 22. The relative movement is actuated by rotating the two turning portions 221 to push the two detent protruding cylinders 211 located on the sliding board 21 to move the sliding board 21, thereby transmitting the relative movement to the upper bolt link mechanism 4 and the lower bolt link mechanism 3 coupled thereto.
As describe above, the driving portion 230 and the pivot portion 231 of the first drive unit 23 are not limited in position on the base 20, therefore, when the first drive unit 23 moves relative to the door handle mechanism 6 of the door lock via the pivot portion 231, the door handle mechanism 6 needs to have a limit function in position and thus imposes a limitation on the design of installation orientation.
FIG. 2B illustrates an unlock transmission mechanism 2a, 2b being installed in an escape door at opposite directions to respectively correspond to the door handle mechanism 6a, 6b installed on the other side of the escape door 1. To open the escape door 1 on its left side as indicated in FIG. 2B, the door handle mechanism 6a is rotated counterclockwise to transmit relative movement to the unlock transmission mechanism 2a. Conversely, to open the escape door 1 on its right side, the door handle mechanism 6a is rotated clockwise to transmit relative movement to the unlock transmission mechanism 2b. As can be seen from the above, the rotating orientation of the door handle mechanism 6a, 6b is configured to be opposite to one another to be installed in an escape door or the like, causing inconveniences in the installation and usage as well as increased material costs.
A need thus exists for a door lock apparatus for escape doors or the like, which can improve on the defects of prior escape door locks in actual usage.